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President Obama's reelection campaign launched a broadside Monday against Mitt Romney, attacking the core of his business resume and calling into question his record as a jobs creator.

In a new website, web video and lengthy television ad set to air in battleground states, the Obama campaign assailed Romney's record at private equity firm Bain Capital.

The effort marked Obama's fiercest swipe yet at the presumptive Republican nominee's business background. Romney's former GOP opponents briefly targeted his Bain Capital days during the primary season, but abandoned that line of criticism amid condemnation from conservatives who claimed those candidates were betraying the party's free-market values.

The Obama campaign, by contrast, will likely not be held back by such intra-party squabbles.

The campaign's two-minute TV ad features steelworkers from a Kansas City, Mo., steel mill that was taken over by Bain and eventually went bankrupt.

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"They made as much money off of it as they could. And they closed it down," Joe Soptic, a steelworker for 30 years, said in the ad.

Another worker likened Bain to a "vampire" that came in and "sucked the life out of us."

Romney's campaign, in response, said the GOP candidate's jobs record still holds up better than Obama's.

"We welcome the Obama campaign's attempt to pivot back to jobs and a discussion of their failed record. Mitt Romney helped create more jobs in his private sector experience and more jobs as governor of Massachusetts than President Obama has for the entire nation," Romney spokeswoman Andrea Saul said in a statement. "President Obama has many questions to answer as to why his administration used the stimulus to reward wealthy campaign donors with taxpayer money for bad ideas like Solyndra, but 23 million Americans are still struggling to find jobs."

The Romney campaign also released a web video Monday afternoon highlighting another steel company, Steel Dynamics, that Romney's old firm helped.

The Obama ad will run in five battleground states: Iowa, Ohio, Pennsylvania, Virginia and Colorado. The campaign declined to describe the size of the ad buy, though it's in the middle of running a $25 million, month-long ad campaign in nine states. A longer version of the ad was being posted online Monday.

The campaign also launched the website RomneyEconomics.com, which tracks Romney's career at Bain and casts the company in an unflattering light, accusing the firm of burdening smaller companies with debt and leaving them to wither.

Romney and his supporters forcefully defended his Bain record during the GOP primary campaign when it first came under attack -- namely, by Newt Gingrich and Rick Perry.

Romney claims the successes at Bain Capital far outweighed the failures. He has said that his firm had a strong overall track record, creating jobs in prominent companies like Staples and Sports Authority, while acknowledging that some companies Bain invested in were unsuccessful.

In an ad released in January, Romney's campaign touted the successful ones. "Mitt Romney helped create and ran a company that invested in struggling businesses, started new ones and rebuilt old ones, creating thousands of jobs," the narrator in the ad said. "Those are the facts."

Romney has accused Obama of attacking free enterprise and called the criticism of his business background an attempt by Democrats to distract voters from the president's record.

The Obama commercial will be coupled with a series of events Obama's campaign is holding this week in Florida, Missouri, Iowa, Nevada and North Carolina to highlight Romney's role at Bain Capital, a company he co-founded.

It's unclear whether Obama, himself, will criticize his Republican rival on the subject when the president appears at events in New York on Monday or whether he'll leave the skewering to campaign surrogates as he prepares to meet with foreign leaders during the G-8 and NATO summits later this week.

Vice President Joe Biden was holding two days of events in Ohio, where he was expected to discuss Romney's role as a corporate buyout specialist.

Obama, hosting his first campaign rally this month in Columbus, Ohio, gave a preview of the new line of attack, saying Romney had "drawn the wrong lessons" from his business experience at the helm of Bain.

"He doesn't seem to understand that maximizing profits by whatever means necessary -- whether through layoffs or outsourcing or tax avoidance or union-busting -- might not always be good for the average American or for the American economy," Obama said then.

Romney, a multimillionaire, left Bain in 1999 to run the Salt Lake City Olympic Games, but maintained a financial interest in the company after departing.

Obama's new ad focuses on the plight of company GST Steel, though the job losses there occurred after Romney had left Bain.

Bain was the majority shareholder in GST Steel beginning in 1993. The company eventually filed for bankruptcy in 2001, a period in which the U.S. steel industry was roiled by a flood of cheap steel imports. About 750 workers lost their jobs, and were left without any health benefits and reduced pensions. The federal government was forced to infuse $44 million into the company's underfunded pension plan.

Bain received $12 million on its $8 million initial investment and at least $4.5 million in consulting fees, according to a January report by Reuters.

The Associated Press contributed to this report.